CN115836492A

CN115836492A - Signaling transmission with assistance of enhanced NR type II CSI feedback

Info

Publication number: CN115836492A
Application number: CN202180049159.0A
Authority: CN
Inventors: S·穆鲁加内森; F·阿特利; M·弗伦内; 高世伟; H-L·麦塔宁; 张鑫林
Original assignee: Telefonaktiebolaget LM Ericsson AB
Current assignee: Telefonaktiebolaget LM Ericsson AB
Priority date: 2020-07-10
Filing date: 2021-07-09
Publication date: 2023-03-21
Also published as: EP4179638A1; US20230291441A1; KR20230034379A; CA3185386A1; WO2022009178A1; JP2023533692A

Abstract

A method for reporting Channel State Information (CSI) from a wireless device to a radio network node is provided. More specifically, the wireless device receives an indication from a radio network node indicating a subset of Frequency Domain (FD) basis vectors out of a full set of FD basis vectors. Thus, the wireless device uses the indicated subset of FD basis vectors to calculate CSI corresponding to the enhanced type II port selection codebook and reports the CSI to the radio network node. The methods disclosed herein make it possible to reduce the complexity and signaling overhead for reporting CSI based on a selected subset of FD basis vectors.

Description

Signaling transmission with assistance of enhanced NR type II CSI feedback

RELATED APPLICATIONS

The present application claims the benefit of provisional patent application serial No. 63/050,550, filed on 10/7/2020, the disclosure of which is incorporated herein by reference in its entirety.

Technical Field

The techniques of this disclosure generally relate to signaling for frequency-domain and spatial-domain basis indications to facilitate enhanced New Radio (NR) type II Channel State Information (CSI) feedback using angle and delay reciprocity.

Background

Codebook-based precoding

The multiple antenna technology can significantly improve the data rate and reliability of a wireless communication system. Performance is particularly improved if both the transmitter and receiver are equipped with multiple antennas, which results in a multiple-input multiple-output (MIMO) communication channel. Such systems and/or related techniques are commonly referred to as MIMO.

The NR standard is currently evolving with enhanced MIMO support. The core part in NR is to support MIMO antenna deployment and MIMO related techniques such as spatial multiplexing. The spatial multiplexing mode aims at achieving high data rates under favorable channel conditions. Fig. 1 provides an illustration of spatial multiplexing operations.

As can be seen, the information-bearing symbol vector s is multiplied by N _T r precoder matrix W for distributing the transmission energy over N _T (corresponds to N) _T One antenna port) in a subspace of the dimensional vector space. The precoder matrix is typically selected from a codebook of possible precoder matrices and is typically indicated by means of a Precoder Matrix Indicator (PMI), which specifies a unique precoder in the codebook for a given number of symbol streams. R symbols of s respectively correspond to layers, and r is referred to as a transmission rank. In this way, since the two can be at the same timeMultiple symbols are transmitted simultaneously on the inter/frequency resource elements (TFREs), so spatial multiplexing is achieved. The number of symbols r is typically adapted to the current channel characteristics.

NR uses Orthogonal Frequency Division Multiplexing (OFDM) in the downlink (and DFT-precoded OFDM for rank 1 transmission in the uplink), so for a particular TFRE (or alternative data TFRE number N) on subcarrier N, the received N _R X 1 vector y _n Modeled by the following equation:

y _n ＝H _n Ws _n +e _n

wherein e _n Is the noise/interference vector obtained as an implementation of a random process. The precoder W may be a wideband precoder, which is constant in frequency or frequency selective.

The precoder matrix W is typically chosen to match N _R ×N _T MIMO channel matrix H _nr Thereby resulting in so-called channel dependent precoding. This is also commonly referred to as closed-loop precoding and essentially aims to focus the transmit energy into the subspace, which is powerful in the sense of transmitting most of the transmit energy to the UE.

In closed-loop precoding for NR downlink, the UE sends a recommendation to the gNB for a suitable precoder to use based on channel measurements in the downlink. The gNB configures the UE to provide feedback according to the CSI-ReportConfig and may transmit Channel State Information (CSI) -Reference Signals (RSs) (CSI-RSs) and configure the UE to use measurements of the CSI-RSs to feed back recommended precoding matrices selected by the UE from the codebook. A single precoder considered to cover a large bandwidth (wideband precoding) can be fed back. It is also beneficial to match the frequency variation of the channel and instead feed back one frequency selective precoding report (e.g., several precoders) per subband. This is an example of a more general case of CSI feedback, which includes feedback of other information in addition to the recommended precoders to assist the gnnodeb in subsequent transmissions to the UE. Such other information may include Channel Quality Indicators (CQIs) and transmission Rank Indicators (RIs). In NR, CSI feedback may be wideband, where one CSI is reported for the entire channel bandwidth, or frequency selective, where one CSI is reported for each subband. Herein, a sub-band is defined as a number of consecutive resource blocks ranging between 4 to 32 PRBSs depending on the bandwidth part (BWP) size.

Given CSI feedback from the UE, the gNB determines transmission parameters that the gNB wishes to use for transmission to the UE, including a precoding matrix, a transmission rank, and a Modulation and Coding Scheme (MCS). These transmission parameters may be different from the recommendations made by the UE. The transmission rank, and thus the number of spatial multiplexing layers, is reflected in the number of columns of the precoder W. For efficient performance, it is important to select a transmission rank that matches the channel properties.

2D antenna array

The presented disclosure may be used with two-dimensional antenna arrays, and some of the presented embodiments use such antenna arrays. Such an antenna array may be (partially) aligned with the horizontal dimension N _h Number of corresponding antenna columns, and vertical dimension N _v Number of corresponding antenna rows and polarization N different from each other _p The number of corresponding dimensions. Thus, total number of antennas = N _h N _v N _p′ . It should be noted that the concept of an antenna is non-limiting as it may refer to any virtualization (e.g., linear mapping) of physical antenna elements. For example, a physical subelement pair may be fed the same signal and therefore share the same virtualized antenna port.

An example of a 4 x 4 array with dual polarized antenna elements is shown in figure 2.

Precoding may be interpreted as multiplying a signal with different beamforming weights for each antenna prior to transmission. A typical way is when designing the precoder codebook, e.g. considering H _h 、N _v And N _p The precoder is adjusted to adapt to the antenna shape factor.

Channel state information reference signal (CSI-RS)

For CSI measurement and feedback, a CSI-RS is defined. The CSI-RS is transmitted on each antenna port and is used by a User Equipment (UE) to measure downlink channels between each transmit antenna port and each receive antenna port in the UE. The transmit antenna ports are also referred to as CSI-RS ports. The number of antenna ports supported in the NR is {1,2,4,8,12,16,24,32}. By measuring the received CSI-RS, the UE can estimate the channel that the CSI-RS is traversing, including the radio propagation channel and antenna gain. The CSI-RS used for the above purpose is also referred to as non-zero power (NZP) CSI-RS.

The CSI-RS may be configured to be transmitted in a specific Resource Element (RE) in one slot and a specific plurality of slots. Fig. 3 shows an example of CSI-RS REs for 12 antenna ports, where 1 RE per RB per port is shown.

In addition, an Interference Measurement Resource (IMR) is also defined in NR for the UE to measure interference. The IMR resource contains 4 REs, 4 adjacent REs in frequency in the same OFDM symbol or 2 by 2 adjacent REs in both time and frequency in a time slot. By measuring both NZP CSI-RS based channels and IMR based interference, the UE may estimate the effective channel and noise plus interference to determine CSI (e.g., rank, precoding matrix, and channel quality).

Further, a UE in the NR may be configured to measure interference based on one or more NZP CSI-RS resources.

CSI framework in NR

In NR, a UE may be configured with multiple CSI report settings and multiple CSI-RS resource settings. Each resource arrangement may contain multiple resource sets, and each resource set may contain up to 8 CSI-RS resources. For each CSI report setting, the UE feeds back a CSI report.

Each CSI report setting contains at least the following information:

CSI-RS resource set for channel measurement

IMR resource set for interference measurement

Optionally, a set of CSI-RS resources for interference measurement

Time domain behavior, i.e. periodic, semi-persistent or aperiodic reporting

Frequency granularity, i.e. wideband or subband

CSI parameters to report, such as RI, PMI, CQI and Resource Indicator (CRI) of CSI-RS, in case of multiple CSI-RS resources in a resource set

Codebook type, i.e. type I or II, and codebook subset restriction

Measurement limits

Subband size. One of two possible subband sizes is indicated, the range of values depending on the bandwidth of BWP. One CQI/PMI is fed back per subband (if configured for subband reporting).

When a set of CSI-RS resources in a CSI reporting setting contains multiple CSI-RS sources, the UE selects one of the CSI-RS, and the UE also reports the CRI to indicate to the gNB the resources of the selected CSI-RS in the set of resources, and the RI, PMI, and CQI associated with the selected CSI-RS resource.

For aperiodic CSI reporting in NR, multiple CSI reporting settings may be configured and triggered simultaneously, each setting having a different set of CSI-RS resources for channel measurements and/or a set of resources for interference measurements. In this case, multiple CSI reports are aggregated and sent from the UE to the gNB in a single Physical Uplink Shared Channel (PUSCH).

NR Rel-16 enhanced type II port selection codebook

An enhanced type II (eType II) Port Selection (PS) codebook is introduced in Rel-16, which codebook is intended for beamformed CSI-RS, where each CSI-RS port covers a small part of the cell coverage area with high beamforming gain (compared to non-beamformed CSI-RS). Although this depends on the implementation of the gNB, it is generally assumed that each CSI-RS port is transmitted in a 2D spatial beam with a main lobe having an azimuth pointing angle and an elevation pointing angle. The actual precoder matrix used for CSI-RS is transparent to the UE. Based on the measurements, the UE selects the best CSI-RS port and makes a recommendation to the gNB for DL transmission. The eType II PS codebook may be used by the UE to feed back the selected CSI-RS ports and as a way to combine the selected CSI-RS ports. The configured CSI-RS ports may be viewed as a set of Spatial (SD) bases, and a subset of the SD bases is determined and reported back by the UE.

Structure, configuration and reporting of eType II PS codebooks

For a given transmission layer l, where l ∈ { 1.,. V } and v is RI, all Frequency Domains (FD) are uniqueThe precoder matrix of the element is composed of a size P _CSI-RS ×N ₃ (i.e. P) _CSI-RS Row and N ₃ Columns) of matrix W _l The method comprises the following steps:

·P _CSI-RS is the number of single polarized CSI-RS ports.

·N ₃ ＝N _SB Xr is the number of PMI subbands, where

The o value R = {1,2} (PMI subband size indicator) is RRC-configured.

○N _SB Is the number of CQI subbands, which is also RRC configured.

Set the RI value v according to the configured higher layer parameter typeII-RI-recovery-r 16.

The UE should not report v >4.

Precoder matrix W _l Can be factorized into

And W _l Normalized such that for l =1,.., v,

port selection matrix W ₁ ：W ₁ Is of size P _CSI-RS A 2L port selection precoder matrix, which may be decomposed into

Wherein:

·W _PS is of a size including 0s and 1s

The port selection matrix of (1). The selected port is denoted by 1s, which is common for both polarizations.

L is the number of CSI-RS ports selected per polarization. The supported L values can be found in table 1.

The selected CSI-RS port is formed by two parameters d and i _1，1 And (4) jointly determining. From the first ⁱ _1，1 Starting with a port, only selecting every d-th portPort (note that port number is determined by the gNB).

The value of o d is configured by the higher layer parameter portSelectionSamplingSize, where d ∈ {1,2,3,4} and

○i _1，1 is determined by the UE based on CSI-RS measurements, wherein

I that the UE should select _1，1 And feeding back to the gNB.

·W ₁ Common to all layers.

Frequency domain compression matrix W _f，l ：W _f，l Is that the size of the layer l is N ₃ ×M _v The FD domain compression matrix of (1), wherein:

·

is the number of selected FD basis vectors, which depends on the rank indicator v and the RRC configuration parameter p _v 。p _v The support values of (a) can be found in table 1.

·

Wherein

Is derived from having a size N ₃ N of x 1 ₃ Quadrature DFT basis vectors

M of (1) _v Each size is N ₃ FD basis vector of x 1.

For N ₃ Less than or equal to 19, and one-step free selection is adopted.

■ For each layer, FD base selection

Bit combination indicationThe indicator indicates. In TS38.214, the combination indicator is indexed by the index i _1，6l Given, where | corresponds to the layer index. The combined index is reported by the UE to the gbb per-layer per PMI.

For N ₃ (> 19), a two-step selection with a common intermediate subset of layers (IntS) is used.

■ In a first step, a window-based layer common IntS selection is used, which is selected by M _initial And (4) parameterizing. IntS includes FD base vector mod (M) _initial+n ，N ₃ ) Wherein =0,1.,. N' ₃ -1 and N' ₃ ＝2M _v . In TS38.214, the UE passes the parameter i _1，5 The selected intss are reported to the gNB, which is reported as part of the PMI.

■ Second step subset selection of each layer in part 2 reported by CSI

Bit combination indicator indication. In TS38.214, the combination indicator is indexed by the index i _1，6，l Given, where l corresponds to the layer index. The combined index is reported by the UE to the gbb per-layer per PMI.

·W _f，i Is layer specific.

Linear combination coefficient matrix

·

Is of size 2 LxM _v Including 2L CSI-RSs for selecting

Selected M of ports _v 2LM with linear combination of FD basis vectors _v A coefficient.

For layer l, only

A subset of the coefficients is non-zero and reported. The rest(s)

The individual unreported coefficients are considered to be zero.

○

Is the maximum number of non-zero coefficients per layer, where β is the RRC configuration parameter. The supported β values are shown in table 1.

O for v ∈ {2,3,4}, the total number of non-zero coefficients summed across all layers

Should satisfy

Selected coefficient subset of each layer is of size 2LM _v In a bit map of

1s indicates that the bitmap is included in part 2 of the CSI report.

○

(wherein

) Is included in a part of the CSI report so that the payload of part 2 of the CSI report can be known.

Should quantify

The amplitude and phase of the medium coefficients for reporting.

·

Is layer specific.

Table 1: for L, p _v Rel-16eType II PS codebook parameter configuration for sum beta

FDD based reciprocal operation

In Frequency Division Duplex (FDD) operation, uplink (UL) and Downlink (DL) transmissions are performed on different frequencies, so the propagation channels in the UL and DL are not reciprocal like in the Time Division Duplex (TDD) case. Nevertheless, some physical channel parameters (e.g., delay and angle to different clusters), which depend on the spatial characteristics of the channel rather than the carrier frequency, are reciprocal between UL and DL. These characteristics can be exploited to obtain FDD transmission based on partial reciprocity. The reciprocal part of the channel can be combined with the non-reciprocal part to obtain the complete channel. The estimate of the non-reciprocal part may be obtained by feedback from the UE.

Fig. 4 illustrates one procedure of the reciprocity-based FDD transmission scheme in 4 steps, assuming that the NR rel.16 enhanced type II port selection codebook is used.

In step 1, the UE configures SRS by the gNB and the UE transmits SRS in the UL for the gNB to estimate angles and delays for different clusters associated with different propagation paths.

In step 2, in the gNB implementation algorithm, the gNB selects the dominant cluster according to the estimated angular delay power spectrum profile, and for each of the selected clusters, the gNB precodes (e.g., beamforms) according to the obtained angular and/or delay estimates and transmits one CSI-RS port per polarization to the UE.

In step 3, the gNB has configured the UE to measure CSI-RS and the UE measures the received CSI-RS ports and then determines type II CSI comprising RI, PMI for each layer and CQI. The precoding matrix indicated by the PMI includes the selected beam (e.g., precoded CSI-RS port) and the corresponding best phase and amplitude for bringing the selected beam in phase. The phase and amplitude of each beam is quantized and fed back to the gNB.

In step 4, the gNB implementation algorithm calculates a DL precoding matrix for each layer based on the selected beams and corresponding amplitude and phase feedback and performs Physical Downlink Shared Channel (PDSCH) transmission. The transmission is directly based on a feedback (PMI) precoding matrix (e.g., SU-MIMO transmission), or the transmission precoding matrix is obtained from an algorithm that combines CSI feedback from multiple UEs (MU-MIMO transmission). In this case, precoders (e.g., zero-forcing precoders or regularized ZF precoders) derived based on the precoding matrix (including CSI reports from co-scheduled UEs). The final precoder is typically scaled such that the transmit power of each power amplifier is not overwritten.

Such reciprocity-based transmission can potentially be utilized in codebook-based DL transmission for FDD, e.g., to reduce feedback overhead in the UL when a codebook is selected using NR type II ports. Another potential benefit is reduced complexity in CSI computation in the UE.

Type II port selection codebook for FDD operation based on angle/delay reciprocity

FD base W if Rel.16 enhanced type II port selection codebook is used for FDD operation based on angle and/or delay reciprocity _f It still needs to be determined by the UE. Therefore, in CSI reporting, the feedback overhead for indicating which FD bases are selected may be large, especially when the number N3 of PMI subbands is large. Furthermore, the computational complexity at the UE for evaluating and selecting the best FD base also increases with the increase in N3.

In methods proposed outside this disclosure, delay reciprocity between UL and DL, the gNB is used to book a subset of FD bases based on estimated delay information to selected clusters in the UL. The gNB may then indicate the FD base to the UE

Is determined. The UE may then evaluate and select FD basis vectors within the predetermined subset.

In a proposed approach outside this disclosure, the gNB determines the angles and delays of different clusters by analyzing the angular delay power spectrum of the channel. For example, the 8 x 10 grid at the left of fig. 5 shows the angular delay power spectrum of an UL channel with 8 angular bins and 10 delay taps, where each shaded square represents the power level of a given cluster at a particular angle and delay. Based on angular reciprocity, in this example, the gNB selects the 2 strongest clusters and precodes one CSI-RS port per polarization for transmission to each cluster (i.e., 4 CSI-RS ports in total). In the right part of fig. 5, there are only 4 taps in the delay domain in the two beamformed channels (i.e. the two beamformed channels correspond to two selected clusters), while there are 10 taps in the original channel. Thus, the remaining 4 delay taps (which can be converted to have 4 vectors)

FD basis) may be transmitted by the gNB to the UE such that the UE need only select the best frequency basis vector from the 4 FD basis vector candidates instead of 10. Thus, in the present example, overhead for indicating what FD base to select may be reduced, and computational complexity at the UE for selecting the best FD base may be reduced.

In another approach proposed outside of this disclosure, the gNB pre-compensates the delay of each beamformed channel so that the strongest path of all beamformed channels reaches the UE at the same time. As can be seen in fig. 6, after pre-compensating the delays of the beamformed channels, the number of delay taps is reduced to 3 in the two beamformed channels corresponding to the two selected clusters. This is in contrast to the 10 delay taps in the original channel. Furthermore, since the zeroth delay component (which corresponds to the zeroth FD basis vector, i.e., DC basis) is always present, the gNB only needs to signal the remaining 2 FD basis vectors to the UE

Therefore, the UE only needs to select the best frequency basis vector from the 2 FD basis vector candidates, instead of the 4 FD basis vector candidates as in the example in fig. 5. Thus, in this example, not only is the overhead for indicating which FD components have been selected reduced, but the overhead for reporting the corresponding LC coefficients from the UE to the gNB may also be reduced. Furthermore, the computational complexity at the UE for selecting the optimal FD base may be reduced.

Thus, the previously proposed solution may be used to reduce the CSI feedback overhead for indicating which FD basis vectors to use and for combining the corresponding phases and amplitudes of the selected FD and SD bases. The previously proposed solution also reduces the computational complexity of the UE in selecting the best FD basis vector.

Disclosure of Invention

Embodiments disclosed herein include a method for reporting Channel State Information (CSI) from a wireless device to a radio network node. More specifically, the wireless device receives an indication from a radio network node indicating a subset of Frequency Domain (FD) basis vectors out of a full set of FD basis vectors. Thus, the wireless device uses the indicated subset of FD basis vectors to calculate CSI corresponding to the enhanced type II port selection codebook and reports the CSI to the radio network node. The methods disclosed herein make it possible to reduce the complexity and signaling overhead for reporting CSI based on a selected subset of FD basis vectors.

In an aspect, a method performed by a wireless device for reporting CSI is provided. The method includes receiving, from a radio network node, an indication indicating a subset of FD basis vectors from a full set of FD basis vectors for each group of transmission layers. The method also includes calculating CSI corresponding to the enhanced type II port selection codebook using the indicated subset of FD basis vectors. The method further comprises reporting the CSI to the radio network node.

In another aspect, the full set of FD basis vectors includes a length equal to N ₃ Is determined.

In another aspect, N ₃ Determined by the following higher layer parameters: numberOfPMISubbandsPerCQISubband and csi-reporting band.

In another aspect, receiving an indication indicative of a subset of FD basis vectors comprises: an indication is received in a control message indicating the selected subset of FD basis vectors.

In another aspect, the control message is a medium access control, MAC, control element, CE.

In another aspect, the MAC CE includes a field configured to indicate a subset of FD basis vectors from the full set of FD basis vectors.

In another aspect, the fields in the MAC CE include one of: n is a radical of ₃ Bit map of bits and

a bitmap of bits.

In another aspect, the MAC CE includes a plurality of fields, each field configured to indicate, for a respective one of the plurality of layers, a subset of FD basis vectors from the full set of FD basis vectors.

In another aspect, each of the plurality of fields in the MAC CE includes one of: n is a radical of ₃ Bit map of bits and

a bit map of bits.

In another aspect, receiving the indication indicating the subset of FD basis vectors comprises receiving the indication indicating the subset of FD basis vectors in downlink control information, DCI.

In another aspect, the DCI includes a field corresponding to a codepoint and configured to indicate a subset of FD basis vectors from a full set of FD basis vectors.

In another aspect, a field in the DCI includes CSI-AssociatedReportConfigInfo corresponding to a code point.

In another aspect, the method further comprises: receiving, from a radio network node, a configuration of a CSI-RS resource having a set of CSI-reference signal CSI-RS ports and an indication indicating one or more of: one or more non-zero power CSI-RS ports and one or more zero power CSI-RS ports. The method also includes performing channel measurements on one or more non-zero power CSI-RS ports.

In another aspect, calculating CSI using the indicated subset of FD basis vectors comprises: the CSI is calculated based on all indicated subsets of FD basis vectors. Reporting CSI includes: an index indicating a subset of the indicated subset of FD basis vectors is not reported as part of the enhanced type II port selection precoding matrix indicator, PMI, report.

In another aspect, calculating CSI using the indicated subset of FD basis vectors comprises: the CSI is calculated based on the selected subset of the indicated subset of FD basis vectors. Reporting CSI includes: reporting as part of an enhanced type II port selection precoding matrix indicator, PMI, report an index indicating a selected subset of the indicated subset of FD basis vectors.

In one aspect, a wireless device is provided. The wireless device includes processing circuitry. The processing circuitry is configured to cause the wireless device to receive, from the radio network node, an indication indicating a subset of FD basis vectors from the full set of FD basis vectors for each group of transmission layers. The processing circuit is further configured to cause the wireless device to calculate CSI corresponding to the enhanced type II port selection codebook using the indicated FD basis vector. The processing circuitry is further configured to cause the wireless device to report CSI to the radio network node.

In another aspect, the processing circuitry is configured to cause the wireless device to perform any of the steps of any of the claims performed by the wireless device.

In an aspect, a method performed by a radio network node for enabling a wireless device to report CSI is provided. The method includes providing an indication to a wireless device indicating a subset of FD basis vectors from a full set of FD basis vectors for each group of transmission layers. The method also includes receiving CSI from the wireless device.

In another aspect, the method further includes determining a subset of FD basis vectors from the full set of FD basis vectors based on one or more uplink measurements performed on sounding reference signals, SRSs, received from the wireless device.

In another aspect, providing an indication indicative of the subset of FD basis vectors comprises: the selected subset of FD basis vectors is indicated in a control message.

In another aspect, the control is a MAC CE.

In another aspect, the MAC CE includes a field configured to indicate an indicated subset of FD basis vectors from among the full set of FD basis vectors.

a bit map of bits.

In another aspect, the MAC CE includes a plurality of fields, each field configured to indicate, for a respective one of the plurality of layers, an indicated subset of FD basis vectors from among the full set of FD basis vectors.

a bit map of bits.

In another aspect, providing an indication indicative of the subset of FD basis vectors comprises: an indication is provided that indicates a subset of FD basis vectors in the DCI.

In another aspect, a field in the DCI includes CSI-AssociatedReportConfigInfo corresponding to a codepoint.

In another aspect, the method further comprises: providing, to a wireless device, a configuration of a CSI-RS resource having a set of CSI-RS ports and an indication indicating: one or more non-zero power CSI-RS ports in the CSI-RS resource and/or one or more zero power CSI-RS ports in the CSI-RS resource. The method also includes receiving, from the wireless device, channel measurements performed based on the one or more non-zero power CSI-RS ports.

In another aspect, receiving CSI comprises one of: receiving CSI that does not include an index indicating a subset of the indicated subset of FD basis vectors as part of an enhanced type II port selection PMI report, and receiving CSI that includes an index indicating a selected subset of the indicated subset of FD basis vectors as part of an enhanced type II port selection PMI report.

In one aspect, a radio network node includes processing circuitry. The processing circuitry is configured to cause the radio network node to provide an indication to the wireless device indicating a subset of FD basis vectors out of a full set of FD basis vectors for each group of transmission layers. The processing circuitry is further configured to cause the radio network node to receive CSI from the wireless device.

In another aspect, the processing circuitry is further configured to cause the radio network node to perform any of the steps in any claim performed by the radio access node.

Drawings

The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present disclosure and, together with the description, serve to explain the principles of the disclosure.

Fig. 1 is a schematic diagram providing an exemplary illustration of a New Radio (NR) spatial multiplexing operation;

FIG. 2 is a schematic diagram of an exemplary four-by-four (4 × 4) array with dual polarized antenna elements;

fig. 3 is a diagram of an exemplary Channel State Information (CSI) reference signal (CSI-RS RE) for 12 antenna ports;

fig. 4 is a diagram providing an exemplary illustration of a process for a reciprocity-based Frequency Division Duplex (FDD) transmission scheme;

fig. 5 is a schematic diagram providing an exemplary illustration of an angular delay power spectrum of an UL channel having 8 angular bins and 10 delay taps;

fig. 6 is a diagram providing an exemplary illustration of a reduction in the number of delay taps to 3 after pre-compensating the delay for the beamformed channel;

FIG. 7 illustrates one example of a cellular communication system in which embodiments of the present disclosure may be implemented;

fig. 8 is a flow diagram of an example method performed by a wireless device for reporting CSI in accordance with an embodiment of the disclosure;

fig. 9 is a flow diagram of an example method performed by a radio network node for enabling a wireless device to report CSI in accordance with an embodiment of the present disclosure;

fig. 10 is a flow diagram of an example method for a wireless device to report CSI based on signaling provided by a radio network node;

fig. 11 is a flow diagram of an example method performed by a radio network node for providing signaling to a wireless device for reporting CSI;

fig. 12 is a schematic diagram of an exemplary illustration of a selected subset of Frequency Domain (FD) basis vectors indicated to a Medium Access Control (MAC) Control Element (CE);

fig. 13 is a schematic diagram illustrating an example MAC CE for indicating a selected subset of FD basis vectors to a wireless device configured in accordance with another embodiment of the present disclosure;

figure 14 is a schematic block diagram of a radio access node according to some embodiments of the present disclosure;

figure 15 is a schematic block diagram illustrating virtualized embodiments of radio access nodes in accordance with some embodiments of the present disclosure;

fig. 16 is a schematic block diagram of a radio access node according to some other embodiments of the present disclosure;

fig. 17 is a schematic block diagram of a wireless communication device in accordance with some embodiments of the present disclosure;

fig. 18 is a schematic block diagram of a wireless communication device according to some other embodiments of the present disclosure;

fig. 19 is a schematic diagram of a communication system according to an embodiment of the present disclosure;

fig. 20 is a schematic diagram of a UE, a base station, and a host computer according to an embodiment of the present disclosure;

fig. 21 is a flow diagram illustrating a method implemented in a communication system according to one embodiment of the present disclosure;

fig. 22 is a flow diagram illustrating a method implemented in a communication system according to one embodiment of the present disclosure;

fig. 23 is a flow diagram illustrating a method implemented in a communication system in accordance with one embodiment of the present disclosure; and is provided with

Fig. 24 is a flow diagram illustrating a method implemented in a communication system according to one embodiment of the present disclosure.

Detailed Description

The embodiments set forth below represent information that enables those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure.

The radio node: as used herein, a "radio node" is a radio access node or a wireless communication device.

A radio access node: as used herein, a "radio access node" or "radio network node" or "radio access network node" is any node in a Radio Access Network (RAN) of a cellular communication network that is operative to wirelessly transmit and/or receive signals. Some examples of radio access nodes include, but are not limited to, a base station (e.g., an NR base station (gbb) in a third generation partnership project (3 GPP) fifth generation (5G) New Radio (NR) network or an enhanced or evolved node B (eNB) in a 3GPP Long Term Evolution (LTE) network), a high power or macro base station, a low power base station (e.g., a micro base station, a pico base station, a home eNB, etc.), a relay node, a network node that implements part of the functionality of a base station (e.g., a network node that implements a gbb central unit (gbb-CU) or a network node that implements a gbb distributed unit (gbb-DU)), or a network node that implements part of the functionality of some other type of radio access node.

A core network node: as used herein, a "core network node" is any type of node in the core network or any node that implements core network functionality. Some examples of core network nodes include, for example, a Mobility Management Entity (MME), a packet data network gateway (P-GW), a Service Capability Exposure Function (SCEF), a Home Subscriber Server (HSS), and so forth. Some other examples of core network nodes include nodes implementing: an access and mobility management function (AMF), a User Plane Function (UPF), a Session Management Function (SMF), an authentication server function (AUSF), a Network Slice Selection Function (NSSF), a Network Exposure Function (NEF), a Network Function (NF) repository function (NRF), a Policy Control Function (PCF), a Unified Data Management (UDM), etc.

The communication device: as used herein, a "communication device" is any type of device that is capable of accessing an access network. Some examples of communication devices include, but are not limited to: a mobile phone, a smart phone, a sensor device, a meter, a vehicle, a household appliance, a medical device, a media player, a camera, or any type of consumer electronics device, such as but not limited to a television, a radio, a lighting fixture, a tablet computer, a laptop computer, or a Personal Computer (PC). The communication device may be a portable, handheld, computer-comprised or vehicle-mounted mobile device that supports communication of voice and/or data over a wireless or wired connection.

A wireless communication device: one type of communication device is a wireless communication device, which may be any type of wireless device that accesses (i.e., is served by) a wireless network (e.g., a cellular network). Some examples of wireless communication devices include, but are not limited to: user equipment devices (UEs), machine Type Communication (MTC) devices, and internet of things (IoT) devices in a 3GPP network. Such a wireless communication device may be or may be integrated in a mobile phone, a smartphone, a sensor device, a meter, a vehicle, a household appliance, a medical device, a media player, a camera, or any type of consumer electronics device, such as, but not limited to, a television, a radio, a lighting device, a tablet computer, a laptop computer, or a PC. The wireless communication device may be a portable, handheld, computer-comprised or vehicle-mounted mobile device that supports communication of voice and/or data over a wireless connection.

A network node: as used herein, a "network node" is any node that is part of the RAN or core network of a cellular communication network/system.

Note that the description given herein focuses on 3GPP cellular communication systems, and thus 3GPP terminology or terminology similar to 3GPP terminology is often used. However, the concepts disclosed herein are not limited to 3GPP systems.

Note that in the description herein, the term "cell" may be referred to; however, especially with respect to the 5G NR concept, beams may be used instead of cells, and it is therefore important to note that the concepts described herein apply equally to both cells and beams.

There are currently certain challenge(s). The problem of how to signal selected frequency-domain basis vectors and/or spatial-domain Channel State Indication (CSI) -Reference Signal (RS) (CSI-RS) ports from the gNB to the UE is not addressed. Furthermore, signaling a selected subset of FD basis vectors and/or CSI-RS ports may increase downlink control overhead. In this regard, it may be desirable to efficiently signal a selected subset of FD basis vectors and/or CSI-RS ports with minimal downlink control overhead while ensuring signaling reliability.

Certain aspects of the present disclosure and embodiments thereof may provide solutions to the above-mentioned and other challenges. In the present disclosure, a method is presented for signaling, by a gNB, a selected subset of Frequency Domain (FD) basis vectors from a full set of FD basis vectors and/or a selected subset of CSI-RS ports from a full set of CSI-RS ports to a UE. Solutions based on both Media Access Control (MAC) Control Element (CE) signaling and Downlink Control Information (DCI) signaling are proposed to reduce the overhead associated with signaling subsets of FD basis vectors and/or CSI-RS ports. Based on the proposed solution, a method is also proposed where the UE uses a subset of the CSI-RS ports and/or FD basis vectors of all useful signaling transmissions for CSI reporting for the enhanced (i.e. Rel-16) type II port selection codebook, which reduces UE complexity and CSI reporting overhead. Further methods are proposed in which the UE performs further FD basis vector and/or CS-RS port sub-selection based on a subset of the signaled FD basis vectors (instead of the full set of FD basis vectors) and/or a subset of CSI-RS ports, which reduces UE complexity.

Furthermore, a method for signaling a CSI-RS port to be measured, which can be signaled in combination with a selected subset of FD basis vectors, is proposed. Particular embodiments disclosed herein include at least the following:

1. method for signaling transmission of FD base vector full set N from network to UE ₃ A method of selecting a subset of FD basis vectors, wherein the FD basis vectors are of length equal to N ₃ The method comprises the following steps:

the UE calculates CSI corresponding to the enhanced type II port selection codebook using the indicated FD basis vector.

2. The method of 1, wherein the selected subset of FD basis vectors is signaled by the MAC CE.

3. The method according to any of 1 or 2, wherein the length in the MAC CE is N ₃ Each bit in the field of (a) indicates whether an FD basis vector is selected.

4. The method according to any of 1-3, wherein up to a maximum number of FD base vectors may be selected and signaled in the MAC CE.

5. The method of 4, wherein the maximum number of FD basis vectors is determined by one or more higher layer configured parameters.

6. The method of 1, wherein the selected subset of FD basis vectors is signaled via DCI.

7. The method according to any of 1-6, wherein the UE calculates CSI using all indicated FD basis vectors.

8. The method according to 7, wherein the UE does not index i _1，5 And i _1，6，l The feedback report is part of an enhanced type II port selection PMI report.

9. The method of any of claims 1-6, wherein the UE calculates the CSI using the indicated subset of FD basis vectors.

10. The method according to 9, wherein the UE can index i _1，5 And i _1，6，l Is part of an enhanced type II port selection PMI report.

11. The method according to any of claims 1-10, wherein the gNB additionally indicates to the UE a subset of non-zero power CSI-RSs among the set of configured CSI-RS ports to use for performing channel measurements.

12. The method according to any of claims 1-10, wherein the method further comprises the gNB additionally indicating to the UE a zero-power CSI-RS among the set of configured CSI-RS ports.

13. The method of 12, wherein the UE performs channel measurements on CSI-RS ports of the set of CSI-RS ports that are not indicated as zero-power CSI-RS ports.

Various embodiments are presented herein that address one or more of the problems disclosed herein.

In one embodiment, a method performed by a wireless device for reporting CSI is provided.The method includes receiving a full set of FD basis vectors (e.g., N) from a network node (e.g., eNB) ₃ ) Selected subset of FD basis vectors. The method also includes calculating CSI corresponding to an enhanced (e.g., rel-16) type II port selection codebook using the selected subset of FD basis vectors. The method also includes reporting the CSI to the network node.

In another embodiment, a method performed by a base station (e.g., eNB) for enabling a wireless device to report CSI is provided. The method includes indicating a full set of FD basis vectors (e.g., N) to a wireless device ₃ ) Selected subset of FD basis vectors. The method also includes reporting CSI from the wireless device.

Certain embodiments may provide one or more of the following technical advantages. The main advantages of the proposed solution are as follows:

reduced CSI reporting overhead.

UE complexity is reduced.

Reduced signaling overhead for indicating the selected subset of FD basis vectors.

Fig. 7 illustrates one example of a cellular communication system 700 in which embodiments of the present disclosure may be implemented. In the embodiment described herein, the cellular communication system 700 is a 5G system (5 GS) comprising a next generation RAN (NG-RAN) and a 5G core (5 GC). In this example, the RAN includes base stations 702-1 and 702-2, which include NR base stations (gnbs) and optionally next generation enbs (ng-enbs) in a 5GS (e.g., LTE RAN nodes connected to a 5 GC), which control corresponding (macro) cells 704-1 and 704-2. Base stations 702-1 and 702-2 are collectively referred to herein as base station 702 and individually as base station 702. Likewise, (macro) cells 704-1 and 704-2 are collectively referred to herein as (macro) cells 704, and individually as (macro) cells 704. The RAN may also include a plurality of low power nodes 706-1 to 706-4 that control corresponding small cells 708-1 to 708-4. The low-power nodes 706-1 through 706-4 may be small base stations (such as pico base stations or femto base stations) or Remote Radio Heads (RRHs), etc. It is noted that, although not shown, one or more of small cells 708-1 to 708-4 may alternatively be provided by base station 702. Low power nodes 706-1 through 706-4 are collectively referred to herein as low power nodes 706, and are individually referred to as low power nodes 706. Likewise, small cells 708-1 to 708-4 are collectively referred to herein as small cells 708, and are individually referred to as small cells 708. The cellular communication system 700 further comprises a core network 710, which in a 5G system (5 GS) is referred to as 5GC. Base station 702 (and optionally low power node 706) is connected to core network 710.

Base station 702 and low power node 706 provide service to wireless communication devices 712-1 through 712-5 in corresponding cells 704 and 708. The wireless communication devices 712-1 through 712-5 are collectively referred to herein as wireless communication devices 712 and individually as wireless communication devices 712. In the following description, the wireless communication device 712 is often a UE, but the disclosure is not so limited.

Prior to discussing specific embodiments of the present disclosure, a method performed by a wireless device (e.g., 712-1, 712-2, 712-3) and a method performed by a radio network node (e.g., 702-1, 702-2, 706-1, 706-2, 706-3, 706-4) for supporting specific embodiments are first provided with reference to fig. 8 and 9.

Fig. 8 is a flow diagram of an example method performed by a wireless device for reporting CSI in accordance with an embodiment of the present disclosure. The wireless device receives an indication from the radio network node indicating a subset of FD basis vectors from the full set of FD basis vectors for each group of transmission layers (step 800). In one embodiment, the wireless device may receive an indication in a control message indicating a subset of FD basis vectors (step 800-1). In another embodiment, the wireless device may receive an indication in DCI indicating a subset of FD basis vectors (step 800-2). The wireless device may receive, from a network node, a configuration of a CSI-RS resource having a set of CSI-RS ports and an indication indicating: one or more non-zero power CSI-RS ports in a CSI-RS resource and/or one or more zero power CSI-RS ports in a CSI-RS resource (step 802). Accordingly, the wireless device may perform channel measurements on one or more non-zero power CSI-RS ports (step 804). The wireless device uses the indicated subset of FD basis vectors to calculate CSI corresponding to the enhanced type II port selection codebook (step 806). In one embodiment, the wireless device may calculate CSI based on all indicated subsets of FD basis vectors (step 806-1). In another embodiment, the wireless device may calculate CSI based on a selected subset of the indicated subset of FD basis vectors (step 806-2). The wireless device reports CSI to the radio network node (step 808). In one embodiment, the wireless device may not report an index indicating the indicated subset of FD basis vectors as part of a Precoding Matrix Indicator (PMI) report for enhanced type II port selection (step 808-1). In another embodiment, the wireless device may report an index indicating the selected subset of the indicated subset of FD basis vectors as part of an enhanced type II port selection PMI report (step 808-2).

Fig. 9 is a flow diagram of an example method performed by a radio network node for enabling a wireless device to report CSI in accordance with an embodiment of the present disclosure. The radio network node may determine a subset of FD basis vectors out of the full set of FD basis vectors based on one or more uplink measurements performed on the SRS received from the wireless device (step 900). The radio network node provides an indication to the wireless device indicating a subset of FD basis vectors for each set of transmission layers (step 902). In one embodiment, the radio network node may provide an indication indicating the subset of FD basis vectors in a control message (step 902-1). In another embodiment, the radio network node may provide an indication in the DCI indicating the subset of FD basis vectors (step 902-2). The radio network node may provide the configuration of the CSI-RS resource with the set of CSI-RS ports and an indication indicating: one or more non-zero power CSI-RS ports in the CSI-RS resource and/or one or more zero power CSI/RS ports in the CSI-RS resource (step 904). Accordingly, the radio network node may receive channel measurements performed based on the one or more non-zero power CSI-RS ports from the wireless device (step 906). The radio network node may then receive CSI from the wireless device (block 908). In one embodiment, the radio network node may receive CSI that does not include an index indicating a subset of the indicated subset of FD basis vectors as part of a selection PMI report for an enhanced type II port (step 908-1). In another embodiment, the radio network node may receive CSI including an index indicating a selected subset of the indicated subset of FD basis vectors as part of a PMI report selected for an enhanced type II port (step 908-2).

Fig. 10 is a flow diagram of an example method performed by a wireless device for reporting CSI. A wireless device receives a full set of FD basis vectors (e.g., N) from a radio network node (e.g., a gNB) ₃ ) Selected subset of FD basis vectors (step 1000). In one embodiment, the wireless device may receive a subset of FD basis vectors in a MAC CE (step 1000-1). In another embodiment, the wireless device may receive the subset of FD basis vectors in DCI (step 1000-2). The wireless device may receive an indication (e.g., by MAC CE or DCI) from the network node indicating: one or more non-zero power CSI-RSs or one or more zero power CSI/RS ports among the configured CSI-RS port set (step 1002). Accordingly, the wireless device may perform channel measurements on one or more non-zero power CSI-RS ports (step 1004). The wireless device uses the selected subset of FD basis vectors to calculate CSI corresponding to an enhanced (e.g., rel-16) type II port selection codebook (step 1006). In one embodiment, the wireless device may calculate CSI based on all selected subsets of FD basis vectors (step 1006-1). In another embodiment, the wireless device may calculate CSI based on the selected subset of FD basis vectors (step 1006-2). The wireless device reports CSI to the radio network node (step 1008). In one embodiment, the wireless device may not index i _1，5 And i _1，6，j Reporting a portion of a Precoding Matrix Indicator (PMI) report selected for an enhanced type II port (step 1008-1). In another embodiment, the wireless device may index i _1，5 And i _1，6，j Reporting a portion of a Precoding Matrix Indicator (PMI) report selected for an enhanced type II port (step 1008-2).

Fig. 11 is a flow diagram of an example method performed by a radio network node (e.g., a gNB) for enabling a wireless device to report CSI. The radio network node may determine a full set of FD basis vectors (e.g., N) based on one or more uplink measurements performed on SRS received from the wireless device ₃ ) FD basis vectors (step 1100). Radio network node indicating selection to wireless deviceFD basis vector subset (step 1102). In one embodiment, the radio network node may indicate the selected subset of FD basis vectors in the MAC CE (step 1102-1). In another embodiment, the radio network node may indicate the selected subset of FD basis vectors in DCI (step 1102-2). The radio network node may provide an indication (e.g., by a MAC CE or DCI) to the wireless device indicating: one or more non-zero power CSI-RS ports or one or more zero power CSI/RS ports (step 1104). Accordingly, the radio network node may receive from the wireless device channel measurements performed based on the one or more non-zero power CSI-RS ports (step 1106). The radio network node may then receive CSI from the wireless device (block 1108). In one embodiment, the radio network node may not receive the index i _1，5 And i _1，6，j As part of the enhanced type II port selection PMI report (step 1108-1). In another embodiment, the radio network node may receive the index i _1，5 And i _1，6，j As part of the enhanced type II port selection PMI report (step 1108-2).

Throughout this disclosure, the terms "frequency domain basis vector" and "spatial domain basis vector/matrix" are used.

Note that the term "frequency domain basis vector" may not be part of the 3GPP standard specification. Conversely, a "frequency domain basis vector" (FD basis vector) may be defined as having a length equal to N ₃ A set of orthogonal complex vectors (e.g., DFT vectors). For example, in the 3GPP specification, the nth frequency domain basis vector (where N = {0, 1.,. N., N =) ₃ -1 }) can be defined as follows:

note that in some cases, the symbol f _n，l Can be used to represent and correspond to l ^th N associated with precoding matrix of spatial layer ^th Frequency domain basis vectors.

Similarly, the term "spatial basis vector/matrix" (SD basis vector/matrix) may not be part of the 3GPP standard specification. On the contraryThe "space-domain basis vector/matrix" may be defined as having a length equal to N ₁ N ₂ A set of 2-dimensional orthogonal complex vectors (e.g., 2-dimensional DFT vectors).

1-Signaling of frequency-domain basis vectors by MAC CE

In this embodiment (e.g., steps 1000, 1000-1, 1102-1), N is indicated to the UE by the gNB through the MAC CE ₃ A selected subset of FD basis vectors among the FD bases. As shown in the example of fig. 12, includes N ₃ Bit (or)

Octet) of a bit map _n ，n∈{0，1，...，N ₃ -1} for indicating the selected subset of FD basis vectors for CSI feedback using the type II port selection codebook. Bit F set to a value of 1 _n Indicating selection of the nth FD base vector f _n . If bit F _n Set to a value of 0, then this means that the nth FD basis vector f is not selected _n 。

Due to field F in MAC CE _n Is of length N ₃ (it is the number of PMI subbands), field F _n Depends on the following parameters, both of which are higher layer configured (e.g., RRC configured) for the UE:

a parameter R configured by a higher layer parameter number OfPMISubbandsPerCQISubband, and

·csi-ReportingBand(N _sB ) The number of medium CQI subbands, csi-ReportingBand, is in turn determined by the subband size configured by the higher layer parameter subband size and the total number of PRBs in the bandwidth part.

The above correlation is due to the number N of PMI subbands ₃ Given by the product of R and the number of Channel Quality Indicator (CQI) subbands in csi-reporting band (recall N) ₃ ＝N _SB ×R)。

Fig. 12 is an example MAC CE configured according to one embodiment of the present disclosure for a selected subset of FD basis vectors indicated from a network node to a wireless device. In some embodiments, as shown in fig. 10, the MAC CE used to indicate the selected subset of FD basis vectors further includes a serving cell ID and/or a bandwidth part (BWP) ID, which corresponds to a CSI reporting configuration configured with type II port selection codebook-based CSI feedback. In addition, a configuration ID of the CSI report configuration (i.e., CSI-ReportConfig ID) is also included as part of the MAC CE as shown in fig. 12.

The motivation for including these in the MAC CE is the need to flexibly indicate the selected FD base set to the UE, which is configured with CSI feedback based on different type II port selection codebooks in different CSI reporting configurations in the same or different BWPs in different serving cells configured to the UE.

Although each selected FD basis vector is indicated in fig. 12 by a single bit in the bit map, the selected FD basis vectors may be indicated in other forms. For example, in another example MAC CE, each selected FD basis vector may be encoded by one of the MAC CEs

A bit indication. In this case, to select the M FD basis vectors, it may be necessary to assign the M FD basis vectors to the selected FD basis vectors

One bit is included in the MAC CE. In another example, one or more combination indicators may be used in the MAC CE to indicate one or more selected FD basis vectors to the UE.

1.1-embodiment in which the number of selected FD bases in a MAC CE is determined by parameters configured by higher layers

In one embodiment, the number of FD base vectors selected and indicated by the MAC CE is determined by

Given, where R is given by the higher layer parameter number OfPMISubbandsPerCQISubband, and N ₃ Is the number of PMI subbands. Parameter p _v，max P is determined by a higher layer parameter paramCombination-r16 _v V e [ 1,2 ] and p _v The maximum p in upsilon e {3,4} _v The value is obtained.

TABLE 2 for p _v Code book parameter ofNumber arrangement

In the above table, when the paramCombination-r16 is configured as 4, p _v，max Given by 1/4, because p corresponds to upsilon ∈ {1,2} _υ A value higher than p corresponding to upsilon e {3,4} _υ The value is obtained. Once the MAC CE indicates to the UE the selection of the FD basis vector, the UE may perform the following procedure: if the UE indicates that RI equals 1 or 2, the UE will use all M indicated in the MAC CE _max The FD basis vectors are used for type II port selection CSI feedback. Therefore, in this case, the UE does not have to perform FD basis vector selection, and the UE does not have to feed back the selected FD basis vector to the gNB. This means that the UE does not have to report the index i _1，5 (for N) ₃ >19 reported as part of PMI in CSI report of NR Rel-16 enhanced type II port selection codebook). Similarly, index i _1，6，i (which indicates the selected subset of FD basis vectors to the gNB in a CSI report that selects a codebook based on NR Rel-16 type II ports) need not be reported by the UE to the gNB as part of the PMI report. This means significant CSI reporting overhead savings compared to Rel-16 type II enhanced CSI reporting.

If the UE indicates that RI equals 3 or 4, the UE will use Mm indicated in the MAC CE _ax A subset of the FD basis vectors are used for type II port selection CSI feedback. Thus, in this case, the UE only indicates M from the MAC CE _max Total number N of FD basis vectors rather than frequency domain bases ₃ Performs FD-based selection, which reduces complexity at the UE. Note that in this case, the UE may index i _1，5 And i _1，6，l To select a portion of a PMI report for a rel-16 type II port.

In an alternative embodiment, if the UE indicates a Rank Indicator (RI) equal to 1 or 2, the UE will use M indicated in the MAC CE _max A subset of the FD basis vectors are used for type II port selection CSI feedback. Thus, in this alternative embodiment, the UE only indicates M from the MAC CE _max FD base vector ofNot the total number of frequency domain bases N ₃ Among others, FD basis vector selection is performed, which reduces the complexity of the UE. Note that in this case, the UE may index i _1，5 And i _1，6，l Is part of a Rel-16 type II port selection PMI report.

In some embodiments, when M indicated in the MAC CE is selected by the UE _max Upon identifying a subset of FD basis vectors among the FD basis vectors, one or more i to be reported by the UE as part of a Rel-16 type II port selection PMI report _1，6，l When, the combination coefficient table C (x, y) in table 5.2.2.5-4 of 3gpp ts38.214 is used.

1.2-embodiment to change the number of selected FD basis vectors indicated in MAC CE

In this embodiment (e.g., step 1100), the gNB flexibly selects the number M of FD basis vectors selected and indicated by the MAC CE based on measurements on the uplink channel _flex Without being influenced by e.g. p _υ ，N ₃ And the limitation of higher layer parameters of R.

In some cases, the maximum number of FD basis vectors that can be selected may be defined by higher layer parameters. For example, the maximum number of FD basis vectors may be selected by

Given, where R is given by the higher layer parameter number OfPMISubbandsPerCQISubband, and N ₃ Is the number of PMI subbands. The parameter p _v，max P is determined by a higher layer parameter paramCombination-r16 _v V e [ 1,2 ] and p _v The maximum p among v ∈ {3,4} _v The value is obtained. Thus, in this example embodiment, the number of FD basis vectors M selected _flex ＝1，2…，M _max 。

In a variation on this embodiment, the UE will use all M indicated in the MAC CE _flex The FD basis vectors are used for type II port selection CSI feedback (e.g., step 806-1). Therefore, in this case, the UE does not have to perform FD basis vector selection, and the UE does not have to selectIs fed back to the gNB. This is beneficial for reducing UE complexity. Furthermore, there is an overhead saving and the UE does not have to index i _1，5 And i _1，6，l The report selects part of the PMI report for the rel-16 type II port (e.g., steps 1008-1, 1108-1).

In another variation of this embodiment, the UE will use M indicated in the MAC CE _flex A subset of the FD basis vectors are used for type II port selection CSI feedback (e.g., step 1006-2). Thus, in this alternative embodiment, the UE only indicates M from the MAC CE _flex Total number N of FD basis vectors instead of FD basis vectors ₃ Performs FD basis vector selection, which reduces complexity at the UE. Note that in this case, the UE may index i _i，5 And i _1，6，l To select a portion of a PMI report for a Rel-16 type II port (e.g., steps 1008-2, 1108-2).

1.3-embodiments that indicate different numbers of selected FD basis vectors for different numbers of layers

In this embodiment, the number of selected FD basis vectors may be indicated in the MAC CE per layer or per group of layers. Fig. 13 is an exemplary MAC CE for indicating a selected subset of FD basis vectors from a network node to a wireless device, configured according to another embodiment of the disclosure. As shown in fig. 11, for each layer l (l = 1.... V), bits (or v) are included

Octets) of a bitmap

Is used to indicate a selected subset of FD basis vectors for CSI feedback using a type II port selection codebook with l layers. Bit set to value 1

Indicating that the nth FD base vector f associated with the precoding matrix corresponding to the l spatial layer is selected _n，l . If bit

Is set to a value of 0, then this means that the nth FD basis vector f is not selected _n，l 。

Although the example in FIG. 13 shows one field associated with each layer l

This embodiment can also be generalized to the case where one field in a MACCE is associated with a set of layers. For example, one such field may be associated with layer l =1 or 2, while another field may be associated with layer l =3 or 4.

In some embodiments, the maximum number of FD basis vectors that may be selected may be defined by for each layer or group of layers.

2-Signaling of frequency-domain basis vectors over DCI

Another possibility of the selected FD basis vectors is indicated by DCI (e.g., steps 1000, 1000-1, 1102-2).

In one embodiment, the list of different selected FD basis vectors may be preconfigured by higher layers (e.g., by RRC), and a field in the DCI may select and indicate one of the preconfigured lists to the UE. For example, as shown below, one such list may be configured in terms of CSI-Association ReportConfigInfo in a CSI-Aperiodic TriggerStateList information element. In the example below, the FDBasisVectorId may be in the range {0,1 ₃ -1 }. With this example embodiment, different selected FD basis vector lists may be triggered by different codepoints in the CSI request field. That is, codepoint 1 in the CSI request field may trigger a first CSI-AssociatedReportConfigInfo containing a first list of selected FD-based vectors, and codepoint 2 in the CSI request field may trigger a second CSI-AssociatedReportConfigInfo containing a second list of selected FD-based vectors.

CSI-Aperiodic TriggerStateList information element

Dynamic signaling of null-domain basis vectors in 3-DCI or MAC CE

This embodiment (e.g., steps 1002, 1004, 1106, 1108) solves the problem of the number of strong clusters in the channel between the gNB and the UE varying over time. This means that the number of CSI-RS ports required also varies. Unless this problem is solved, the UE needs to configure a CSI-RS resource that contains an upper limit on the number of CSI-RS ports that are expected to be needed. Alternatively, this embodiment may be used when sharing an N-port CSI-RS resource configuration among multiple UEs. For a given UE, only a subset of the L ports is of interest, as the other N-L ports are intended for other UEs.

To have flexibility in the value of N, a UE may be configured with multiple NZP CSI-RS resources with different numbers N of CSI-RS ports, and select the appropriate number of ports, i.e. NZP CSI-RS resources, for a given UE based on UL measurements. For example, if it is determined that there are L =6 dominant directions from the UE according to a specific criterion based on UL measurements, an NZP CSI-RS resource with N =8 (N > = L) ports may be selected by the UE and triggered for CSI feedback, where zero power is transmitted in two of the 8 ports. This will minimize overhead since at a given point in time the number of ports used is closer to the number of ports needed.

To further reduce UE processing complexity, the gNB decides that N-L ports transmitting at zero power (since L ports are sufficient) or L ports with non-zero power may also be signaled to the UE. In this case, the UE will ignore N-L ports with zero power and measure and compute CSI based on only L active (i.e., non-zero power) ports.

The UE may also select L1 ports (or beams) downward from the L ports (or beams) and report back the L1 selected ports and corresponding CSI coefficients. Considering that only L ports are used in the actual CSI measurement instead of N ports and the port index ranges from 0 to L-1 instead of 0 to N-1, the overhead of dynamic signaling with non-zero ports is further reduced in this case.

In one embodiment, the ports with non-zero power are always mapped to the first L CSI-RS ports in the N-port NZP CSI-RS resource. Thus, the value of L or N-L is signaled to the UE. Since the NZP CSI-RS resources can always be selected such that L > N-L, signaling N-L can have less overhead. Considering that N =4, 8,12,16,24,32 is supported for the type II port selection codebook in NR, a maximum of 3 bits is sufficient to signal N-L inactive ports in DCI.

The signaling transmission may be done in DCI or MAC CE. In case of MAC CE, alternatively, P may be used _CSI-RS A bit map of/2 bits, where each bit is associated with a CSI-RS port in each of two polarizations. A pair of non-zero power CSI-RS ports in different polarizations can be formed by combining P _CSI-RS The corresponding bit of the/2 bits is set to "1" to indicate. This will provide more flexibility in the case that N CSI-RS ports may be shared by multiple UEs and different UEs may use different CSI-RS ports.

In some embodiments, signaling for CSI-RS ports with non-zero power is equivalent to signaling for spatial basis vectors.

In some embodiments, signaling of a non-zero power CSI-RS port (or a zero power CSI-RS port) may be done in the same MAC CE along with signaling of the selected FD basis vector (as described in the embodiments in the "signaling of frequency domain basis vectors over MAC CE" section above). That is, different fields or bit maps in the MAC CE may indicate a non-zero power CSI-RS port (or a zero power CSI/RS port) and a selected FD basis vector. In another embodiment, the presence of one of these fields may be optional in the MAC CE and controlled by bits in the MAC CE. For example, the indication of the non-zero power CSI-RS port (or zero power CSI/RS port) may be optional in the MAC CE, and a bit or flag in the MAC CE may indicate whether a field indicating the non-zero power CSI-RS port (or zero power CSI-RS port) is present in the MAC CE.

4-common sub-embodiment

4.1-Enabled feature

In some embodiments, the gNB configures a parameter enabledbasisisselection to the UE such that the parameter selects use of a corresponding MAC CE of the FD basis vector. For example, this parameter may be included in the IE ServingcellConfig, as follows:

enableFDbasisSelection ENUMERATED{enabled}

OPTIONAL，--Need R

enableFDbasisSelection

when this parameter is present, the Rel-17 feature based on FD basis vector selection of MAC CE is enabled. The network configures this parameter only if the UE is configured with a codebook type set to type II port selection.

In an alternative embodiment, the enabling parameter is used to select the entire feature of the FD basis vector. This may include the MAC CE example in the first embodiment of this section, or RRC-only option, which means that the UE is given FD-base in RRC signaling, or DCI-only option, as described in the section "signaling over DCI frequency-domain basis vectors" above.

In an alternative embodiment, this parameter is used to signal spatial basis selection (or indicate non-zero power or zero power CSI-RS ports), similar to that described above for FD basis vector selection. In an alternative embodiment, this parameter is used to enable both FD and SD basis vector selection.

In yet another embodiment, the parameter may enable FDbasis, or SDbasis, or both.

enableFDSDbasisSelection ENUMERATED{fdBasis，sdBasis，both}

OPTIONAL，--Need R

enableFDbasisSelection

When this parameter is set to fdbasis, the Rel-17 feature of FD base vector selection is enabled. When this parameter is set to sdbasis, the Rel-17 feature of the SD basis vector selection is enabled. When the parameter is set to both, the Rel-17 feature selected by the FD basis vector and the SD basis vector are both enabled. The network configures the parameter only if the UE is configured with a codebook type set to type 2.

In another embodiment, any of the above parameters may be set to enabled if the UE has indicated a corresponding capability.

4.2-timing when MAC CE is assumed valid at UE

According to this embodiment, after the UE transmits an ACK for a receiving MAC CE, the UE applies the FD/SD basis vector indicated in the MAC CE in slot X. The value X may be RRC-coded or may be fixed in the specification.

Fig. 14 is a schematic block diagram of a radio access node 1400 in accordance with some embodiments of the present disclosure. Optional features are indicated by dashed boxes. Radio access node 1400 may be, for example, a base station 702 or 706 or a network node that implements all or part of the functionality of a base station 702 or a gNB as described herein. As shown, the radio access node 1400 includes a control system 1402 that includes one or more processors 1404 (e.g., a Central Processing Unit (CPU), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), etc.), a memory 1406, and a network interface 1408. The one or more processors 1402 are also referred to herein as processing circuits. Further, the radio access node 1400 may include one or more radio units 1410, each radio unit 1410 including one or more transmitters 1412 and one or more receivers 1414 coupled to one or more antennas 1416. In some embodiments, radio unit(s) 1410 are located external to control system 1402 and connected to control system 1402 by, for example, a wired connection (e.g., a fiber optic cable). However, in some other embodiments, radio unit(s) 1410 and possibly antenna(s) 1416 are integrated with control system 1402. The one or more processors 1404 operate to provide one or more functions of the radio access node 1400 as described herein. In some embodiments, the function(s) are implemented in software, for example, stored in the memory 1406 and executed by the one or more processors 1404.

Fig. 15 is a schematic block diagram illustrating a virtualized embodiment of a radio access node 1400 in accordance with some embodiments of the present disclosure. This discussion is equally applicable to other types of network nodes. In addition, other types of network nodes may have similar virtualization architectures. Also, optional features are represented by dashed boxes.

As used herein, a "virtualized" radio access node is an implementation of radio access node 1400 in which at least a portion of the functionality of radio access node 1400 is implemented as virtual component(s) (e.g., by virtual machine(s) executing on physical processing node(s) in the network (s)). As shown, in this example, the radio access node 1400 may include a control system 1402 and/or one or more radio units 1410, as described above. The control system 1402 may be connected to the radio unit(s) 1410 by, for example, fiber optic cables or the like. Radio access node 1400 includes one or more processing nodes 1500 that are coupled to or included as part of network(s) 1502. If present, the control system 1402 or radio unit(s) is connected to the processing node(s) 1500 through the network 1502. Each processing node 1500 includes one or more processors 1504 (e.g., CPUs, ASICs, FPGAs, etc.), memory 1506, and network interface 1508.

In this example, the functionality 1510 of the radio access node 1400 described herein is implemented at one or more processing nodes 1500, or distributed in any desired manner between one or more processing nodes 1500 and the control system 1402 and/or radio unit 1410. In some particular embodiments, some or all of functions 1510 of radio access node 1400 described herein are implemented as virtual components executed by one or more virtual machines implemented in a virtual environment(s) hosted by processing node(s) 1500. Additional signaling or communication between the processing node(s) 1500 and the control system 1402 is used to perform at least some of the desired functions 1510, as will be appreciated by those of ordinary skill in the art. Notably, in some embodiments, control system 1401 may not be included, in which case radio unit(s) 1410 communicate directly with processing node(s) 1500 through appropriate network interface(s).

In some embodiments, a computer program is provided comprising instructions which, when executed by at least one processor, cause the at least one processor to perform the functions of the radio access node 1400 or the functions of a node (e.g. processing node 1500) implementing one or more of the functions 1510 of the radio access node 1400 in a virtual environment according to any of the embodiments described herein. In some embodiments, a carrier comprising the computer program product described above is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as a memory).

Fig. 16 is a schematic block diagram of a radio access node 1400 according to some other embodiments of the present disclosure. Radio access node 1400 includes one or more modules 1600, each implemented in software. Module(s) 1600 provides the functionality of radio access node 1400 described herein. The discussion applies equally to processing node 1500 of fig. 15, where module 1600 may be implemented at one of processing nodes 1500 or distributed across multiple processing nodes 1500 and/or distributed across processing node(s) 1500 and control system 1402.

Fig. 17 is a schematic block diagram of a wireless communication device 1700 in accordance with some embodiments of the present disclosure. As shown, the wireless communication device 1700 includes one or more processors 1702 (e.g., CPUs, ASICs, FPGAs, and/or the like), memory 1704, and one or more transceivers 1706, each transceiver 1706 including one or more transmitters 1708 and one or more receivers 1710 coupled to one or more antennas 1712. As will be appreciated by one of ordinary skill in the art, the transceiver(s) 1706 include radio front-end circuitry connected to the antenna(s) 1712 that is configured to condition signals communicated between the antenna(s) 1712 and the processor(s) 1702. The processor 1702 is also referred to herein as a processing circuit. The transceiver 1706 is also referred to herein as a radio circuit. In some embodiments, the functionality of the wireless communication device 1700 described above may be implemented in whole or in part in software stored in the memory 1704 and executed by the processor(s) 1702, for example. Note that wireless communication device 1700 may include additional components not illustrated in fig. 17, such as, for example, one or more user interface components (e.g., an input/output interface including a display, buttons, a touch screen, a microphone, speaker(s), etc., and/or any other component for allowing input of information to wireless communication device 1700 and/or allowing output of information from wireless communication device 170), a power source (e.g., a battery and associated power circuitry), and so forth.

In some embodiments, there is provided a computer program comprising instructions which, when executed by at least one processor, cause the at least one processor to perform the functions of the wireless communication device 1700 according to any of the embodiments described herein. In some embodiments, a carrier comprising the computer program product described above is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as a memory).

Fig. 18 is a schematic block diagram of a wireless communication device 1700 in accordance with some other embodiments of the present disclosure. The wireless communication device 1700 includes one or more modules 1800, each implemented in software. Module(s) 1800 provide the functionality of the wireless communication device 1700 described herein.

Referring to fig. 19, a communication system includes a telecommunications network 1900 (such as a 3 GPP-type cellular network) including an access network 1902 (such as a RAN) and a core network 1904, according to an embodiment. The access network 1902 includes a plurality of

base stations

1906A, 1906B, 1906C, such as node B, eNB, gNB, or other types of wireless Access Points (APs), each defining a

corresponding coverage area

1908A, 1908B, 1908C. Each

base station

1906A, 1906B, 1906C may be connected to the core network 1904 through a wired or wireless connection 1910. A first UE 1912 located in the coverage area 1908C is configured to wirelessly connect to or be paged by a corresponding base station 1906C. A second UE 1914 in the coverage area 1908A may be wirelessly connected to the corresponding base station 1906A. Although

multiple UEs

1912, 1914 are shown in this example, the disclosed embodiments are equally applicable where only one UE is in the coverage area or where only one UE is connected to a corresponding base station 1906.

The telecommunications network 1900 itself is connected to a host computer 1916, and the host computer 1916 may be implemented in hardware and/or software of a standalone server, a cloud-implemented server, a distributed server, or as a processing resource in a server farm. The host 1916 may be under the ownership or control of the service provider or may be operated by or on behalf of the service provider. The

connections

1918 and 1920 between the telecommunications network 1900 and the host computer 1916 may extend directly from the core network 1904 to the host computer 1916, or may pass through an optional intermediate network 1922. The intermediate network 1922 may be one or a combination of more than one of the following: a public network, a private network, or a hosted network; intermediate network 1922 (if present) may be a backbone network or the internet; in particular, the intermediate network 1922 may include two or more sub-networks (not shown).

The communication system of fig. 19 as a whole enables connection between connected

UEs

1912, 1914 and a host computer 1916. This connection may be described as an over-the-top transport (OTT) connection 1924. The host computer 1916 and connected

UEs

1912, 1914 are configured to communicate data and/or signaling over an OTT connection 1924 using the access network 1902, the core network 1904, any intermediate networks 1922, and possibly other infrastructure (not shown) as an intermediary. OTT connection 1024 may be transparent in the sense that the participating communication devices through which OTT connection 1924 passes are unaware of the routing of uplink and downlink communications. For example, the base station 1906 may or may not be informed of past routes of incoming downlink communications with data originating from the host computer 1916 to be forwarded (e.g., handed over) to the connected UE 1912. Similarly, the base station 1906 need not know the future route of outgoing uplink communications originating from the UE 1912 to the host computer 1916.

An example implementation of the UE, base station and host computer discussed in the preceding paragraphs according to one embodiment will now be described with reference to fig. 20. In the communication system 2000, the host computer 2002 includes hardware 2004, the hardware 2004 including a communication interface 2006, the communication interface 2006 configured to establish and maintain a wired or wireless connection with interfaces of different communication devices of the communication system 2000. The host computer 2002 also includes processing circuitry 2008 that can have storage and/or processing capabilities. In particular, the processing circuitry 2008 may include one or more programmable processors, ASICs, FPGAs, or combinations of these (not shown) suitable for executing instructions. Host computer 2002 further includes software 2010 stored in host computer 2002 or accessible by host computer 2002 and executable by processing circuit 2008. Software 2010 includes host application 2012. The host application 2012 may be used to provide services to remote users, such as the UE2014 connected over an OTT connection 2016 that terminates at the UE2014 and the host computer 2002. In providing services to remote users, the host application 2012 may provide user data that is sent using the OTT connection 16.

The communication system 2000 also includes a base station 2018 provided in a telecommunications system and includes hardware 2020 that enables it to communicate with the host computer 2002 and with the UE 2014. The hardware 2020 may include a communication interface 2022 for interfacing with different communication devices of the communication system 2000 to establish and maintain wired or wireless connections, and a radio interface 2024 for establishing and maintaining at least one wireless connection 2026 with a UE2014, which is located in a coverage area (not shown in fig. 20) served by the base station 2018. Communication interface 2022 may be configured to facilitate connection 2028 with host computer 2002. The connection 2028 may be direct or via a core network of the telecommunications system (not shown in fig. 20) and/or via one or more intermediate networks external to the telecommunications system. In the illustrated embodiment, the hardware 2020 of the base station 2018 also includes processing circuitry 2030, which may comprise one or more programmable processors, ASICs, FPGAs, or a combination of these (not shown) adapted to execute instructions. The base station 2018 also has software 2032 stored internally or accessible through an external connection.

The communication system 2000 also includes the already mentioned UE 2014. The hardware 2034 of UE2014 may include a radio interface 2036 configured to establish and maintain a wireless connection 2026 with a base station serving the coverage area in which UE2014 is currently located. The hardware 2034 of the UE2014 also includes processing circuitry 2038, which may include one or more programmable processors adapted to execute instructions, ASICs, FPGAs, or combinations of these (not shown) adapted to execute instructions. The UE2014 also includes software 2040 stored in or accessible by the UE2014, and executable by the processing circuitry 2038. The software 2040 includes a client application 2042. The client application 2042 is operable to provide services to human or non-human users through the UE2014 in support of the host computer 2002. In the host computer 2022, the executing host application 2012 may communicate with the executing client application 2042 over an OTT connection 2016 that terminates at the UE2014 and the host computer 2002. In providing services to users, the client application 2042 may receive request data from the host application 2012 and provide user data in response to the request data. The OTT connection 2016 may transfer both request data and user data. The client application 2042 may interact with the user to generate user data that it provides.

Note that the host computer 2002, base station 2018, and UE2014 shown in fig. 20 may be similar to or the same as one of the host computer 1916,

base stations

1906A, 1906B, 1906C, and one of the

UEs

1912, 1914, respectively, of fig. 19. That is, the internal workings of these entities may be as shown in fig. 20, and independently, the surrounding network topology may be that of fig. 19.

In fig. 20, the OTT connection 2016 has been abstractly drawn to illustrate communication between the host computer 2002 and the UE2014 through the base station 2018 without explicitly mentioning any intermediate devices and the precise routing of messages through these devices. The network infrastructure can determine a route that can be configured to be hidden from the UE2014 or from the service provider operating the host computer 2002, or both. The network infrastructure may also make decisions that it dynamically changes routing when the OTT connection 2016 is active (e.g., based on load balancing considerations or reconfiguration of the network).

A wireless connection 2026 between UE2014 and base station 2018 is consistent with the teachings of embodiments throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to UE2014 using OTT connection 2016, where wireless connection 2026 forms the last segment.

The measurement process may be provided for the purpose of monitoring data rates, latency, and other factors that one or more embodiments improve. There may also be optional network functionality for reconfiguring the OTT connection 2016 between the host computer 2002 and the UE2014 in response to changes in the measurements. The measurement process and/or network functions for reconfiguring the OTT connection 2016 may be implemented in the software 2010 and hardware 2004 of the host computer 2002 or in the software 2040 and hardware 2034 of the UE2014, or both. In some embodiments, sensors (not shown) may be deployed in or associated with the communication device through which the OTT connection 2016 passes; the sensors may participate in the measurement process by providing values of the monitored quantities of the above examples or providing values of other physical quantities from which software 2010, 2040 may calculate or estimate the monitored quantities. The reconfiguration of OTT connection 2016 may include message format, retransmission settings, preferred routing, etc.; the reconfiguration need not affect base station 2018 and it may be unknown or imperceptible to base station 2018. Such processes and functions may be known and practiced in the art. In particular embodiments, the measurements may involve private UE signaling that facilitates the host computer 2002's measurement of throughput, propagation time, latency, and the like. The measurement can be achieved by: the software 2010 and 2040 causes messages (particularly null messages or "dummy" messages) to be sent using the OTT connection 2016 while it monitors for propagation time, errors, etc.

Fig. 21 is a flow diagram illustrating a method implemented in a communication system in accordance with one embodiment. The communication system includes a host computer, a base station, and a UE, which may be those described with reference to fig. 19 and 20. To simplify the present disclosure, only the reference numerals of fig. 21 will be included in this section. In step 2100, the host computer provides user data. In sub-step 2102 (which may be optional) of step 2100, the host computer provides user data by executing a host application. In step 2104, the host computer initiates transmission of bearer user data to the UE. In step 2106 (which may be optional), the base station sends user data carried in host computer initiated transmissions to the UE according to the teachings of embodiments described throughout this disclosure. In step 2108 (which may also be optional), the UE executes a client application associated with a host application executed by the host computer.

Fig. 22 is a flow diagram illustrating a method implemented in a communication system in accordance with one embodiment. The communication system includes a host computer, a base station, and a UE, which may be those described with reference to fig. 19 and 20. To simplify the present disclosure, only the reference numerals of FIG. 22 will be included in this section. In step 2200 of the method, the host computer provides user data. In an optional sub-step (not shown), the host computer provides user data by executing a host application. In step 2202, the host computer initiates transmission of bearer user data to the UE. According to the teachings of embodiments described throughout this disclosure, transmissions may pass through a base station. In step 2204 (which may be optional), the UE receives user data carried in the transmission.

Fig. 23 is a flow diagram illustrating a method implemented in a communication system in accordance with one embodiment. The communication system includes a host computer, a base station, and a UE, which may be those described with reference to fig. 19 and 20. To simplify the present disclosure, only the reference numerals of fig. 23 will be included in this section. In step 2300 (which may be optional), the UE receives input data provided by the host computer. Additionally or alternatively, in step 2302, the UE provides user data. In sub-step 2304 of step 2300 (which may be optional), the UE provides the user data by executing a client application. In sub-step 2306 of step 2302 (which may be optional), the UE executes a client application that provides user data in response to received input data provided by the host computer. In providing user data, the executed client application may also take into account user input received from the user. Regardless of the particular manner in which the user data is provided, the UE initiates transmission of the user data to the host computer in sub-step 2308 (which may be optional). In step 2310 of the method, the host computer receives user data sent from the UE in accordance with the teachings of the embodiments described throughout this disclosure.

Fig. 24 is a flow chart illustrating a method implemented in a communication system according to one embodiment. The communication system includes a host computer, a base station, and a UE, which may be those described with reference to fig. 19 and 20. To simplify the present disclosure, only the reference numerals of fig. 24 will be included in this section. In step 2400 (which may be optional), the base station receives user data from the UE in accordance with the teachings of embodiments described throughout this disclosure. In step 2402 (which may be optional), the base station initiates transmission of the received user data to the host computer. In step 2404 (which may be optional), the host computer receives user data carried in transmissions initiated by the base station.

Any suitable steps, methods, features, functions or benefits disclosed herein may be performed by one or more functional units or modules of one or more virtual devices. Each virtual device may include a plurality of these functional units. These functional units may be implemented by processing circuitry that may include one or more microprocessors or microcontrollers, as well as other digital hardware, which may include Digital Signal Processors (DSPs), dedicated digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or more types of memory, such as Read Only Memory (ROM), random Access Memory (RAM), cache memory, flash memory devices, optical storage devices, and the like. Program code stored in the memory includes program instructions for executing one or more telecommunications and/or data communications protocols and instructions for performing one or more of the techniques described herein. In some implementations, the processing circuitry may be operative to cause the respective functional units to perform corresponding functions in accordance with one or more embodiments of the present disclosure.

While the processes in the figures may show a particular order of operations performed by certain embodiments of the disclosure, it should be understood that such order is exemplary (e.g., alternative embodiments may perform the operations in a different order, combine certain operations, overlap certain operations, etc.).

Some exemplary embodiments of the present disclosure are as follows.

Example 1: a method performed by a wireless device for reporting channel status is providedA method of information CSI. The method includes one or more of: receiving (1000) a full set of frequency domain FD basis vectors (e.g., N) from a network node (e.g., gNB) ₃ ) A selected subset of FD basis vectors among, calculate (1006) CSI corresponding to an enhanced (e.g., rel-16) type II port selection codebook using the selected FD basis vectors, and report (1008) the CSI to a network node.

Example 2: the full set of FD basis vectors includes length equal to N ₃ Set of orthogonal complex vectors.

Example 3: receiving (800) the subset of FD basis vectors comprises receiving (1000-1) the selected subset of FD basis vectors in a medium access control, MAC, control element, CE.

Example 4: the MAC CE includes a field (e.g., N) ₃ Bit pattern of bits or

A bitmap of bits) configured to indicate a selected subset of FD basis vectors from among a full set of FD basis vectors.

Example 5: the MAC CE includes a plurality of fields (e.g., N) ₃ Bit pattern of bits or

A bitmap of bits), each field configured to indicate, for a respective one of the plurality of layers, a selected subset of FD basis vectors from the full set of FD basis vectors.

Example 6: receiving (1000) the subset of FD basis vectors comprises receiving (1000-2) the selected subset of FD basis vectors in downlink control information, DCI.

Example 7: the DCI includes a field (e.g., CSI-AssociatedReportConfigInfo) corresponding to a codepoint and configured to indicate a selected subset of FD basis vectors from among a full set of FD basis vectors.

Example 8: the method further comprises receiving (1002), from the network node (e.g. by the MAC CE or DCI), an indication indicating: one or more non-zero power CSI reference signal CSI-RS ports or one or more zero power CSI-RS ports. The method also includes performing (1004) channel measurements on one or more non-zero power CSI-RS ports.

Example 9: calculating (1006) CSI using the selected FD basis vectors includes calculating (1006-1) CSI based on all selected FD basis vector subsets. Reporting (1008) the CSI includes not indexing i _1，5 And i _1，6，l The report (1008-1) selects a portion of a PMI report for an enhanced type II port.

Example 10: calculating (1006) CSI using the selected FD basis vectors comprises calculating (1006-2) CSI based on the subset of the selected subset of FD basis vectors. Reporting (1008) the CSI includes indexing i _1，5 And i _1，6，l The report (1008-2) selects a portion of a PMI report for an enhanced type II port.

Example 11: the method also includes providing user data and forwarding the user data to the host computer via transmission to the base station.

Example 12: a method performed by a base station (e.g., a gNB) for enabling a wireless device to report channel state information, CSI, is provided. The method includes one or more of: indicating (1102) a full set of frequency domain FD basis vectors (e.g., N) to a wireless device ₃ ) A selected subset of FD basis vectors, and receiving (1108) CSI from the wireless device.

Example 13: the method further comprises the following steps: a subset of FD basis vectors from the full set of FD basis vectors is determined (1100) based on one or more uplink measurements performed on SRSs received from the wireless device.

Example 14: indicating (1102) the subset of FD basis vectors comprises indicating (1102-1) the selected subset of FD basis vectors in a medium access control, MAC, control element, CE.

Example 15: the MAC CE includes a field (e.g., N) ₃ Bit pattern of bits or

A bitmap of bits) configured to indicate a selected subset of FD basis vectors from the full set of FD basis vectors.

Example 16: the MAC CE includes a plurality of fields (e.g., N) ₃ Bit pattern of bits or

Example 17: indicating (1102) that the subset of FD basis vectors comprises receiving (1102-2) the selected subset of FD basis vectors in downlink control information, DCI.

Example 18: the DCI includes a field (e.g., CSI-AssociatedReportConfigInfo) corresponding to a codepoint and configured to indicate a selected subset of FD basis vectors from among a full set of FD basis vectors.

Example 19: the method also includes providing (1104), to the wireless device (e.g., by the MAC CE or DCI), an indication indicating: one or more non-zero power CSI reference signal CSI-RS ports or one or more zero power CSI-RS ports. The method also includes receiving (1106), from the wireless device, channel measurements performed based on the one or more non-zero power CSI-RS ports.

Example 20: receiving (1108) CSI includes not receiving (1108-1) or receiving (1108-2) an index i _1，5 And i _1，6，l As part of an enhanced type II port selection PMI report.

Example 21: the method also includes obtaining user data and forwarding the user data to the host computer or wireless device.

Example 22: a wireless device for reporting channel state information, CSI, is provided. The wireless device comprising the processing circuitry is configured to perform any of the steps of any of the embodiments performed by the wireless device. The wireless device also includes a power circuit configured to provide power to the wireless device.

Example 23: a base station for enabling a wireless device to report channel state information, CSI, is provided. The base station comprises processing circuitry configured to perform any of the steps of any of the embodiments performed by the base station. The base station also includes a power circuit configured to supply power to the base station.

Example 24: a user equipment, UE, for reporting channel state information, CSI is provided. The UE includes an antenna configured to transmit and receive wireless signals. The UE also includes radio front-end circuitry connected to the antenna and the processing circuitry and configured to condition signals communicated between the antenna and the processing circuitry. The processing circuitry is configured to perform any of the steps of any of the embodiments performed by the wireless device. The UE also includes an input interface connected to the processing circuitry and configured to allow information to be input to the UE for processing by the processing circuitry. The UE also includes an output interface connected to the processing circuitry and configured to output information from the UE that has been processed by the processing circuitry. The UE also includes a battery connected to the processing circuitry and configured to power the UE.

Example 25: a communication system includes a host computer. The host computer includes processing circuitry configured to provide user data, and a communication interface configured to forward the user data to the cellular network for transmission to the user equipment UE. The cellular network comprises a base station having a radio interface and processing circuitry configured to perform any of the steps of any of the embodiments performed by the base station.

Example 26: the communication system further comprises a base station.

Example 27: the communication system further comprises a UE, wherein the UE is configured to communicate with the base station.

Example 28: the processing circuitry of the host computer is configured to execute a host application to provide user data. The UE includes processing circuitry configured to execute a client application associated with a host application.

Example 29: a method implemented in a communication system including a host computer, a base station, and a user equipment, UE. The method includes providing user data at a host computer. The method also includes initiating, at the host computer, transmission of bearer user data to the UE through a cellular network including a base station, wherein the base station performs any of the steps of any of the embodiments performed by the base station.

Example 30: the method also includes transmitting user data at the base station.

Example 31: the method also includes executing, at the UE, a client application associated with the host application by executing the host application to provide user data at the host computer.

Example 32: a user equipment, UE, configured to communicate with a base station. The UE comprises a radio interface and processing circuitry configured to perform the methods of the previous 3 embodiments.

Example 33: a communication system includes a host computer. The host computer includes processing circuitry configured to provide user data, and a communication interface configured to forward the user data to the cellular network for transmission to the user equipment UE. The UE includes a radio interface and processing circuitry, and components of the UE are configured to perform any of the steps of any of the embodiments performed by the wireless device.

Example 34: the cellular network also includes a base station configured to communicate with the UE.

Example 35: the processing circuitry of the host computer is configured to execute a host application to provide user data. The processing circuitry of the UE is configured to execute a client application associated with the host application.

Example 36: a method implemented in a communication system including a host computer, a base station, and a user equipment, UE. The method includes providing user data at a host computer. The method also includes initiating, at the host computer, transmission of bearer user data to the UE over a cellular network including a base station. The UE performs any of the steps of any of the embodiments performed by the wireless device.

Example 37: the method also includes receiving, at the UE, user data from the base station.

Example 38: a communication system includes a host computer. The host computer includes a communication interface configured to receive user data originating from a transmission from a user equipment, UE, to a base station. The UE includes a radio interface and processing circuitry. The processing circuitry of the UE is configured to perform any of the steps of any of the embodiments performed by the wireless device.

Example 39: the communication system also includes a UE.

Example 40: the communication system further comprises a base station. The base station includes a radio interface configured to communicate with the UE, and a communication interface configured to forward user data carried by transmissions from the UE to the base station to the host computer.

Example 41: the processing circuitry of the host computer is configured to execute a host application. The processing circuitry of the UE is configured to execute a client application associated with the host application to provide the user data.

Example 42: the processing circuitry of the host computer is configured to execute the host application to provide the requested data. The processing circuitry of the UE is configured to execute a client application associated with the host application to provide user data in response to the request data.

Example 43: a method implemented in a communication system including a host computer, a base station, and a user equipment, UE. The method includes receiving, at a host computer, user data transmitted from a UE to a base station. The UE performs any of the steps of any of the embodiments performed by the wireless device.

Example 44: the method also includes providing, at the UE, the user data to the base station.

Example 45: the method also includes executing a client application at the UE, thereby providing user data to be transmitted. The method also includes executing, at the host computing, a host application associated with the client application.

Example 46: the method also includes executing the client application at the UE. The method also includes receiving, at the UE, input data for the client application, providing the input data at a host computer by executing a host application associated with the client application. The user data to be transmitted is provided by the client application in response to the input data.

Example 47: a communication system comprising a host computer comprising a communication interface configured to receive user data originating from a transmission from a user equipment, UE, to a base station. The base station comprises a radio interface and processing circuitry. The processing circuitry of the base station is configured to perform any of the steps of any of the embodiments performed by the base station.

Example 48: the communication system further comprises a base station.

Example 49: the communication system also includes a UE. The UE is configured to communicate with a base station.

Example 50: the processing circuitry of the host computer is configured to execute a host application. The UE is configured to execute a client application associated with the host application, thereby providing user data to be received by the host computer.

Example 51: a method implemented in a communication system including a host computer, a base station, and a user equipment, UE. The method includes receiving, at a host computer, user data from a base station originating from a transmission that the base station has received from a UE. The UE performs any of the steps of any of the embodiments performed by the wireless device.

Example 52: the method also includes receiving, at the base station, user data from the UE.

Example 53: the method also includes initiating transmission of the received user data to the host computer at the base station.

Example 54: a method for signaling a full set N of frequency domain FD basis vectors from a network (e.g., an eNB) to a user equipment UE ₃ Selected subset of FD basis vectors. The FD base vectors include a length equal to N ₃ Is determined. The method includes the UE using the selected subset of FD basis vectors to calculate CSI corresponding to an enhanced (e.g., 3GPP Rel-16) type II port selection codebook.

Example 55: the selected subset of FD basis vectors is signaled by the medium access control, MAC, control element, CE.

Example 56: NAC CE comprises a length N ₃ Each bit in the field indicates whether an FD basis vector from the full set of FD basis vectors is selected.

Example 57: the MAC CE is configured to indicate up to a maximum number of FD basis vectors.

Example 58: the maximum number of FD basis vectors is determined by one or more higher layer configured parameters.

Example 59: signaling the selected subset of FD basis vectors by means of downlink control information, DCI.

Example 60: the UE calculates CSI using all selected FD basis vectors.

Example 61: UE will not indexi _1，5 And i _1，6，l The feedback report is part of an enhanced type II port selection PMI report.

Example 62: the UE calculates CSI using the selected subset of FD basis vectors.

Example 63: UE will index i _1，5 And i _1，6，l Is part of an enhanced type II port selection PMI report.

Example 64: the network also indicates to the UE a non-zero power CSI-RS subset among the set of configured CSI-RS ports to perform channel measurements.

Example 65: the network also indicates to the UE a zero-power CSI-RS port among the set of configured CSI-RS ports.

Example 66: the UE performs channel measurements on one or more CSI-RS ports of the set of CSI-RS ports that are not indicated as zero-power CSI-RS ports.

At least some of the following abbreviations may be used in the present disclosure. If there is a discrepancy between the abbreviations, preference should be given to the above usage pattern. If listed multiple times below, the first listed form should be preferred over any subsequently listed forms.

3GPP third Generation partnership project

5G fifth Generation

5GC fifth generation core

5GS fifth Generation System

AF application function

AMF Access and mobility functionality

AN Access network

AP Access Point

ASIC specific integrated circuit

AUSF authentication Server function

BWP Bandwidth portion

CPU central processing unit

CQI channel quality indicator

CSI channel State information

DCI downlink control information

DL Downlink

DN data network

DSP digital signal processor

eNB enhancements or evolved node Bs

EPS evolved packet System

E-UTRA evolved universal terrestrial radio access

FD frequency domain

FDD frequency division Duplex

FPGA field programmable Gate array

gNB new radio base station

gNB DU New radio base station distributed Unit

HSS Home subscriber Server

IMR interference measurement resources

IoT Internet of things

IP Internet protocol

LTE Long term evolution

MAC media access control

MCS modulation and coding scheme

MIMO multiple input multiple output

MME mobility management entity

MTC machine type communication

NEF network expose function

NF network functionality

NR new radio

NRF network function repository function

NSSF network slice selection function

Non-zero power of NZP

OFDM orthogonal frequency division multiplexing

OTT over-the-Top transport

PC personal computer

PCF policy control function

PDSCH physical Downlink shared channel

P-GW packet data network gateway

PMI precoder matrix indicator

PS Port selection

PUSCH physical uplink shared channel

QoS quality of service

RAM random access memory

RAN radio Access network

RE resource units

RI rank indicator

ROM read-only memory

RRH remote radio head

RS reference signal

RTT round trip time

SCEF service capability exposure function

SD space domain

SMF session management function

SRS sounding reference signals

TDD time division duplexing

TFRE time/frequency resource units

UDM unified data management

UE user Equipment

UL uplink

UPF user plane functionality

Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein.

Claims

1. A method performed by a wireless device for reporting channel state information, CSI, comprising:

receiving (800), from a radio network node, an indication indicating a subset of frequency domain FD basis vectors out of a full set of FD basis vectors for each group of transmission layers;

calculating (806) CSI corresponding to an enhanced type II port selection codebook using the indicated subset of FD basis vectors; and

reporting (808) the CSI to the radio network node.

2. The method of claim 1, wherein the full set of FD basis vectors comprises a length equal to N ₃ Is determined.

3. The method of claim 2, wherein N ₃ Determined by the higher layer parameters numberofpmisubbandspercqisband csi-ReportingBand.

4. The method of any of claims 1-3, wherein receiving (800) the indicator indicating the subset of FD basis vectors comprises: receiving (800-1) the indication indicating the subset of FD base vectors in a control message.

5. The method of claim 4, wherein the control message is a Media Access Control (MAC) Control Element (CE).

6. The method of claim 5, wherein the MAC CE comprises a field configured to indicate the subset of FD base vectors from the full set of FD base vectors.

7. The method of claim 6, wherein the field in the MAC CE comprises one of:

N ₃ a bitmap of bits; and

a bit map of bits.

8. The method of claim 5, wherein the MAC CE comprises a plurality of fields, each of the fields configured to indicate, for a respective one of a plurality of layers, the subset of FD base vectors from the full set of FD base vectors.

9. The method of claim 8, wherein each of the plurality of fields in the MAC CE comprises one of:

N ₃ a bitmap of bits; and

a bit map of bits.

10. The method according to any of claims 1 and 2, wherein receiving (800) the indication indicating a subset of FD basis vectors comprises: receiving (800-2) the indication indicating the subset of FD base vectors in downlink control information, DCI.

11. The method of claim 10, wherein the DCI comprises a field corresponding to a codepoint and configured to indicate the subset of FD basis vectors from the full set of FD basis vectors.

12. The method of claim 11, wherein the field in the DCI includes CSI-AssociatedReportConfigInfo corresponding to the codepoint.

13. The method of any of claims 1 to 12, further comprising:

receiving (802), from the radio network node, a configuration of CSI-RS resources with a set of CSI-reference signal, CSI-RS, ports and an indication indicating one or more of:

one or more non-zero power CSI-RS ports in the CSI-RS resource; and

one or more zero-power CSI-RS ports in the CSI-RS resource; and

performing (804) channel measurements based on the one or more non-zero power CSI-RS ports.

14. The method of any one of claims 1 to 13, wherein:

calculating (806) the CSI using the indicated subset of FD basis vectors comprises: calculating (806-1) the CSI based on all indicated subsets of the FD basis vectors; and

reporting (808) the CSI comprises: reporting (808-1) no index indicating the indicated subset of the subset of FD basis vectors as part of an enhanced type II port selection Precoding Matrix Indicator (PMI) report.

15. The method of any one of claims 1 to 13, wherein:

calculating (806) the CSI using the indicated subset of FD basis vectors comprises: calculating (806-2) the CSI based on the indicated selected subset of the subset of FD basis vectors; and

reporting (808) the CSI comprises: reporting (808-2) an index indicating the selected subset of the indicated subset of FD basis vectors as part of an enhanced type II port selection Precoding Matrix Indicator (PMI) report.

16. A wireless device (1700) comprising processing circuitry (1702, 1706) configured to cause the wireless device (1700) to:

receiving (800), from the radio network node, an indication indicating a subset of frequency domain FD basis vectors out of a full set of FD basis vectors for each group of transmission layers;

reporting (808) the CSI to the radio network node.

17. The wireless device of claim 16, wherein the processing circuitry (1702, 1706) is further configured to cause the wireless device (1700) to perform any of the steps of any of claims 2-15.

18. A method performed by a radio network node for enabling a wireless device to report channel state information, CSI, comprising:

providing (902), to the wireless device, an indication indicating a subset of frequency-domain FD basis vectors from a full set of FD basis vectors for each group of transmission layers; and

receiving (908) CSI from the wireless device.

19. The method of claim 18, further comprising: determining (900) the subset of FD basis vectors from the full set of FD basis vectors based on one or more uplink measurements performed on sounding reference signals, SRSs, received from the wireless device.

20. The method of any of claims 18 and 19, wherein providing (902) the indication indicating the subset of FD basis vectors comprises: providing (902-1) the indication indicating the subset of FD basis vectors in a control message.

21. The method of claim 20, wherein the control message is a medium access control, MAC, control element, CE.

22. The method of embodiment 21 wherein the MAC CE includes a field configured to indicate the indicated subset of FD basis vectors from among the full set of FD basis vectors.

23. The method of claim 22, wherein the field in the MAC CE comprises one of:

N ₃ a bitmap of bits; and

a bit map of bits.

24. The method of embodiment 21, wherein the MAC CE comprises a plurality of fields, each configured to indicate, for a respective one of a plurality of layers, the indicated subset of FD basis vectors from among the full set of FD basis vectors.

25. The method of claim 24, wherein each of the plurality of fields in the MAC CE comprises one of:

N ₃ a bitmap of bits; and

a bit map of bits.

26. The method of any of claims 18 and 19, wherein providing (902) the indication indicating the subset of FD basis vectors comprises: providing (902-2) the indication indicating the subset of FD base vectors in downlink control information, DCI.

27. The method of claim 26, wherein the DCI comprises a field corresponding to a codepoint and configured to indicate the subset of FD basis vectors from the full set of FD basis vectors.

28. The method of claim 27, wherein the field in the DCI comprises CSI-AssociatedReportConfigInfo corresponding to the codepoint.

29. The method according to any one of claims 18-28, further comprising:

providing (904), to the wireless device, a configuration of CSI-RS resources with a set of CSI-reference signal, CSI-RS, ports and an indication indicating:

one or more non-zero power CSI-RS ports in the CSI-RS resource; and/or

One or more zero-power CSI-RS ports in the CSI-RS resource; and

receiving (906), from the wireless device, channel measurements performed based on the one or more non-zero power CSI-RS ports.

30. The method according to any of claims 18-29, wherein receiving (908) the CSI comprises one of:

receiving (908-1) the CSI without including an index indicating the indicated subset of the subset of FD basis vectors as part of an enhanced type II port selection Precoding Matrix Indicator (PMI) report; and

receiving (908-2) the CSI including an index indicating a selected subset of the indicated subset of FD basis vectors as part of an enhanced type II port selection PMI report.

31. A radio network node (1400), the radio network node (1400) comprising processing circuitry (1402), the processing circuitry (1402) being configured to cause the radio network node (1400) to:

receiving (908) CSI from the wireless device.

32. The radio network node according to claim 31, wherein the processing circuit (1402) is further configured to cause the radio network node (1400) to perform any of the steps of any of claims 18 to 30.